Q: how to transfer contact details from iphone 5c to iphone 6

Greetings bhabaniprasad,

Welcome to the Apple Support Communities!

I understand that you would like to transfer your contact information from your iPhone 5c to your iPhone 6. There are a few different ways to accomplish this. 

First, if you are using iCloud on your iPhone 5c and Contacts are turned on, you simply need to sign in to that same iCloud account on your iPhone 6 and turn Contacts on. 

Get help using iCloud Contacts - Apple Support

If you do not use iCloud, you can backup your iPhone 5c to iTunes and then restore your iPhone 6 from that backup. 

Back up and restore your iPhone, iPad, or iPod touch using iCloud or iTunes - Apple Support

Cheers,

Joe